1. Field of the Invention
The present invention relates to a machine for pipe maintenance, particularly a machine that facilitates repair and maintenance of water supply and drain pipes placed under the ground by removing foreign substances sticking to the inside of the pipelines.
2. Description of the Related Art
In general, water supply and drain pipes, used to supply water to buildings, such as a house, a commercial building, and a factory, and drain used water from the buildings, are generally under the ground and connected to water supply facilities for supplying water or sewage facilities for treating drained water.
The water supply pipe is a pipe for supplying water into a building as described above, but has a problem in that rust or other foreign substances stick to the inside of the pipelines after the pipes have been under the ground over a long period of time, causing contaminated water to be supplied into the building.
Further, the drain pipe is a pipe for draining sewage used in the building and transporting water to sewage facilities, which also has a problem in that dregs contained in the sewage stick to the inside of the pipelines, such that it is difficult to drain sewage, if in excess, the pipelines are blocked and the sewage cannot be drained and flows backward into the building.
The water supply and drain pipes are currently maintained by periodically putting a self-propelled car equipped with a camera into the pipelines to check the conditions inside the pipelines and then, when a pipe having the inside condition worse than a predetermined reference is found, digging the ground and replacing the pipe that is in bad condition.
According to this method of maintaining the water supply and drain pipes, since it is required to dig the ground and then replace the pipe, not only does this cause high cost to replace the pipe but also obstructs the traffic due to a long construction period. Further, because water supply should be stopped, this inconveniences the residents of the building.
According to a self-propelled car disclosed in Korean Utility Model Registration No. 2003647470000, titled “Self-Propelled Car for Polishing Pipe”, a self-propelled car 1 includes a body 2 equipped with a camera 2a at the upper portion of the front and wheels 2c that are driven by a driving motor 2b at the lower portion of the body 2. The self-propelled car 1 further includes a rotating part 3, a polishing part 4, supporting part 5, and a jet part 6. A rotary motor 3a is provided at the front portion in the body 2, a rotating shaft 3b of the rotary motor 3a is provided frontward to rotate a sprocket 3c and a power transmission 3d, and a rotating boss 3e is provided at the front to support the rotating shaft 3a. The polishing part 4 connects a polishing roller 4a to a rotating link 4b to be driven by the power transmission 3d of the rotating part 3 and contacts with and polishes the inside of a pipe. The supporting part 5 has a support roller 5a connected to a support link 5b such that the upper portion of the body 2 is supported while traveling. The jet part 6 has a rotating nozzle 6a at a side of the camera 2a disposed at the front of the body 2 to jet substances polished by the polishing part 4.
According to the self-propelled car for polishing a pipe, as the body 2 equipped with the camera travels in the pipeline, the polishing roller 4a of the polishing part 4 comes in contact with the inside of the pipeline while the camera checks the inside of the pipeline.
Further, the polishing roller 4a is connected to the power transmission 3d of the rotating part 3, such that it polishes and removes foreign substances sticking to the inside of the pipeline while rotating with the rotating link 4b. 
Therefore, the self-propelled car for polishing a pipe was designed to reduce the cost for replacing a pipe and solve the problems, such as suspending water supply and obstructing traffic due to replacing the pipe when repairing the water supply and drain pipes, by removing foreign substances in the pipe without needing to replace the pipe in order to repair and maintain the pipe.
However, according to the self-propelled car for polishing a pipe, since the rotating link is rotated by a rotational force of one power source and the rotational force of the rotary motor is transmitted to the polishing roller to rotate the rotating roller, load exerted in the polishing roller and the rotating link that are being driven is applied to the rotary motor. As a result, the rotating link and the polishing roller cannot smoothly rotate and the efficiency of polishing was reduced, such that it was difficult to cleanly remove the foreign substances in the pipeline.
Further, the self-propelled car uses the polishing roller, of which the outside comes in contact with the inside of the pipeline, to grind and remove the foreign substances, but the contact area between the outside of the polishing roller and the inside of the pipeline is small, such that it was difficult to effectively remove the foreign substances in the pipeline.
Further, according to the self-propelled car for polishing a pipe, since the rotational directions of the rotating link and the polishing roller are the same, the polishing roller frequently slips while removing the foreign substances, such that it was difficult to effectively remove the foreign substances in the pipeline.